The present invention relates generally to photographic equipment and more particularly to a mechanical mounting assembly for a lens system of such equipment. The invention is more specifically directed toward a drive connection mechanism for a movable lens holder member in the assembly.
In the design of a mounting mechanism for a lens holder member which must be axially moved by operation of an actuator member in the lens system, the provision of drive connection means between the lens holder member and the actuator member may give rise to a variety of operational problems.
One such problem arises due to the fact that mechanical complexity of such a system may give rise to increased production costs. It has been common practice in the art to drivingly connect the actuator member to the lens holding member through a key member which is engaged in a key slot of the stationary tube or barrel of the lens system with these members being fixedly secured to each other by the utilization of screw fasteners or the like. For this reason, the number of parts of the assembly is increased and the machining and assembly steps required are also increased. This necessarily gives rise to difficulty in achieving reduction in the costs of such an assembly.
An additional problem which arises relates to the difficulty of insuring stability of the movable lens during its entire excursion so that the lens itself will be held precisely in position normal to the axis of the lens system. In a lens assembly where the overall length which must be traveled by the lens holding member and the lens along the inner diameter of the barrel is sufficiently long, there occurs less difficulty with regard to the influence of accidental tilting of the movable lens with respect to the optical axis and relative to other lenses in the system to insure appropriate optical performance of the system. However, in a more compact lens assembly, it has been difficult to provide positional stability of the lens holding member through a sufficient length of engagement during operation of the lens system.
This difficulty becomes more pronounced when the actuator member, the lens holding member and the drive connection member such as the key member are assembled in a fixed and secured relationship relative to each other by utilization of fastening members.
Accordingly, the present invention is primarily directed toward the provision of a mechanism for connecting an actuator member through a stationary lens barrel in driving engagement with a lens holder member or sleeve which is fitted on the inner diameter of the lens barrel.
The invention is also directed toward provision of a drive connection mechanism of the character described wherein the number of constituent parts is reduced thereby contributing to easier production techniques and to decrease in the production costs of the system.
Furthermore, the invention, is directed toward provision of an adjustable mounting system for holding the movable lens sleeve within a lens optical system so that the lens may be adjustably confined to the optical axis over its entire excursion within the lens mounting assembly.
Another aim of the invention is the provision of a drive connection mechanism for an adjustable mounting system of the type described which will enable adjustable operation of the optical system while avoiding tilting of the lens with reduced effort and difficulty.
A further goal of the invention is to provide a lens assembly mounting and driving system wherein parts may be made of synthetic resin material by molding techniques thereby contributing to reduction in the costs of manufacture while nevertheless providing for a lens optical system which will assure high levels of performance.